Today, setting up a brand new Orchard website will leave you with an empty, no very shiny website. Would you publish the result of the Blog recipe as is ? Certainly not, you will need to choose a theme at least, and maybe add some nice widgets. If I put
myself in the place of a brand new Orchard user odds are that I don't even know that I can browse for themes on the gallery, and thus I don't spend more time on Orchard, dropping it completely. That's why I think we need a brand new default theme, to improve
the numbers of people going from trying Orchard to people publishing it. The first impression is very important, we need to make a good one.

Looking at Wordpress for instance, when you have a brand new setup it's nice by default. No one would be ashamed of publishing in its brand new state.
Here are the links for the current and upcoming default wordpress themes:

Nothing fancy, but it's clean, you would not be ashamed of having it as your blog design.

But not every one wants a blog, so please don't focus on blogs. Orchard is not just a blog engine, and most users don't use it for blogs, as opposed to Wordpress. So I think the default recipe in conjunction with the default theme should target a corporate
website, and be nice when used for a Blog. So yes, this is somehow related to the new Recipe feature improvements
currently discussed for 1.7

The goals of the new default theme:
1- Good looking, a theme that everyone could enjoy
2- Responsive. People will also judge us on the thoroughness of the implementation, and today's standard is mobile. HTML5 too, but this is already the case with The Theme Machine (TTM)
3- Should have the same zones as TTM for compatibility. This could change if the new Custom Layout feature is ready in time, then we would only have a few theme zones.
4- Touch enable. Take a look at the Microsoft website, you don't need to over, but click on the menu items, and they are stateful. This works perfectly with touch too.
5- Optionally configurable from the admin to select color schemes and default banners/slides.

I have found a few website that I think look like something which could make it as the perfect solution. Just talking in terms of content organization, and overall first reaction:

They have in common a Slider, and a columnized footer. Hierarchical navigation, and tri-zone layout for showing main products/ideas/services on the front page.
Would work for a blog too with sidebars for widgets.

NB: Don't think about buying a theme for those online galleries, as the licence would not allow us to redistribute it. Buying a custom one could be done though, I think we have enough resources and knowledge to create one by ourselves. The Orchard community
is full of talented designers and engineers.

I like the toggle/multi-toggle because it's clean and simple to use, and doesn't take space by default. I think the multi-toggle one would make more sense than the simple, as it can still be simple, and we need to handle at least 2 levels of navigations
by default.

Absolutely agree about the possible pitfalls in dependencies on Bootstrap (or any other similar off the shelf grid-system). Saying that though I think it's likely that with the kind of responsive design which is required the CSS will probably contain lots
of the kind of things which Bootstrap has in it (grids, responsive layout, typography, forms, tables etc). The theme will nessecarily take lots of learnings from Bootstrap et al.

It needs to play well to a number of audiences - for instance: developers (who will be looking to see if it's responsive, flexible and easy to extend/configure) and non-technical decision makers who would in a corporate setting be the people who would sign
off budgets for the developers to use it for real.